Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 061633
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
833 AM PST FRI MAR 6 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE OF HIGH PRES WILL REMAIN THROUGH
THE WEEKEND MAINTAINING A DRY...SUNNY...AND WARMER THAN AVERAGE
WEATHER PATTERN. THE UPPER RIDGE WILL WEAKEN EARLY NEXT WEEK AND A
FRONT MAY BRING RAIN TO THE REGION BY TUESDAY OR WEDNESDAY.
&&

.SHORT TERM...WATER VAPOR PICTURES SHOWED THE UPPER RIDGE REMAINED
JUST OFFSHORE THIS MORNING...WHILE VISIBLE AND IR PICTURES SHOWED
SOME PATCHY CIRRUS SPILLING OVER THE TOP OF THE RIDGE. A LIGHT SE
OFFSHORE FLOW THIS MORNING IS EXPECTED TO SWING AROUND TO A LIGHT N
FLOW BY THIS EVENING LEAVING THE FORECAST AREA DRY AND MILD WITH
PLENTY OF SUN FILTERING THROUGH THE HIGH CLOUDS TODAY.

REMAINDER OF SHORT TERM DISCUSSION UNCHANGED. THE UPPER RIDGE WILL
AMPLIFY OVER THE NE PACIFIC TONIGHT AND PUSH THE FRONT WELL TO THE
NORTH AND THERE SHOULD BE LESS HIGH CLOUDS OVER NW OREGON. WITH
CLEARER SKIES...EXPECT TEMPERATURES TONIGHT AND SATURDAY MORNING TO
BE A COUPLE OF DEGREES COOLER.

HIGH PRESSURE WILL PERSIST THIS WEEKEND WITH LOTS OF SUNSHINE AND
WARMING. MODELS FORECAST 850MB TEMPERATURES TO WARM TO AROUND 11 DEG
C THIS WEEKEND AND EXPECT TEMPERATURES TO WARM TO THE MID 60S INLAND
SATURDAY AND THE UPPER 60S SUNDAY...WHICH IS AROUND 10 DEGREES ABOVE
THE SEASONAL NORMAL. COASTAL TEMPERATURES SHOULD BE IN THE UPPER 50S
TO LOW 60S THIS WEEKEND. TJ
&&

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...MONDAY THROUGH
THURSDAY...THE UPPER RIDGE WILL GRADUALLY BREAK DOWN EARLY NEXT WEEK
AFTER STARTING WITH THE AXIS OVER THE COAST. AS THE UPPER RIDGE
EXPANDS EASTWARD MONDAY...MODELS ARE SHOWING A SOMEWHAT AGGRESSIVE
TROUGH SWING SOUTH FROM ALASKA AND EAST ACROSS BRITISH COLUMBIA. THIS
APPEARS TO OPEN THE DOOR FOR A WARM CORE CUT OFF LOW CENTERED NEAR
150W TO DRIFT TOWARD THE PACNW. THE NORTHERN SHORTWAVE MAY BRING VERY
LIGHT RAIN TO THE FAR NORTHERN REACHES OF THE CWA. THE FILLING UPPER
LOW GETS CLOSE ENOUGH TO THE COAST TO SPREAD RAIN WELL INLAND BY
TUESDAY NIGHT. MODELS HAVE CONSISTENTLY SHOWN SOME LOOSE VERSION OF
THIS SCENARIO FOR A FEW DAYS NOW SO BUMPED POPS UP TO LOW END LIKELY
FROM TUESDAY NIGHT ONWARD.

THE VARIOUS MEDIUM RANGE MODELS DO CONTINUE TO STRUGGLE WITH THE
TRACK OF THE UPPER LOW SO CONFIDENCE IN ACTUAL PRECIPITATION AMOUNTS
REMAINS VERY LOW BUT FIND IT DIFFICULT TO EXPECT ANY AREA GETTING
MORE THAN AN INCH DURING THE TUESDAY THROUGH THURSDAY TIME FRAME.
TEMPERATURES WILL BE MODESTLY WARM WITH SNOW LEVELS FAIRLY HIGH SO
EXPECT NO SIGNIFICANT ADDITION TO THE CASCADE SNOW PACK. /JBONK
GRADUALLY BREAK DOWN EARLY NEXT WEEK AFTER STARTING WITH THE AXIS
OVER THE COAST. AS THE UPPER RIDGE EXPANDS EASTWARD MONDAY.
&&

.AVIATION...VFR NEXT 24 HRS. PATCHY FOG THROUGH 18Z
FRI IN SOUTH WILLAMETTE VALLEY...PRIMARILY NEAR KEUG. EXPECT A
REPEAT OF FOG AT KEUG AFTER 06Z SAT.

KPDX AND APPROACHES...VFR PREVAILING NEXT 24 HOURS. /27

&&

.MARINE...QUIET WEATHER PATTERN OVER THE WATERS FOR THE NEXT
SEVERAL DAYS. HIGH PRES OVER WESTERN WA WITH LOWER PRES OFFSHORE
GIVING LIGHT NE WIND OVER MOST OF THE WATER. HOWEVER THERE IS A
WEAK TROUGH OFF THE SOUTH OREGON COAST BRINGING MORE E-SE WIND TO
THE CENTRAL OREGON COAST. WINDS WILL TRANSITION TO NORTHERLY FOR
THE WEEKEND WITH 15 TO 20 KT GUSTS OVER THE OFFSHORE WATERS SAT
NIGHT AND SUN. A CLOSED UPPER LOW OVER THE CENTRAL PAC MON DRIFTS
CLOSER TO THE CALIFORNIA AND S OREGON COAST TUE AND WED.

SEAS HOLDING IN THE 3 TO 5 FOOT RANGE THROUGH THE 5-DAY FORECAST
PERIOD. SPECTRAL ANALYSIS SUGGESTS THERE WILL BE MULTIPLE 2 OR 3
FOOT COMPONENTS THROUGH TONIGHT...PRIMARILY FROM THE WNW AND SSW.
GUIDANCE HAS COME DOWN ON SEAS IN THE EXTENDED PERIOD AROUND NEXT
WEDNESDAY...AND NOW SHOWS 10 TO 11 FEET WHICH SEEMS MORE
REASONABLE THAN THE TEENS IT WAS SHOWING EARLIER. TUESDAY NIGHT
AND INTO WEDNESDAY APPEARS TO BE THE NEXT CHANCE FOR ANY
SIGNIFICANT WINDS OR SEAS. BOWEN/WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND


THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.



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